Mauro Raggi PADME Kick-off meeting Frascati, 20th-21st April 2015 PADME ecal studies Mauro Raggi PADME Kick-off meeting Frascati, 20th-21st April 2015

Outline Ecal and the gamma measurement Possible Ecal materials Ecal geometry constraints Ecal in the PADME MC Ecal Read out schematics Conclusion and prospects M. Raggi PADME kick-off meeting 20/04/2015

Aims of the PADME Ecal PADME Ecal is the heart of the PADME invisible experiment Calorimeter performance reflects on the M2Miss resolution which is a crucial ingredient of the invisible decay sensitivity Ecal is supposed to measure E, position and time of the cluster Dx,Dy ~ 2-3 mm s(E)/E ~ 1-2%/sqrt(E) for energy as low as 50-100MeV DT < 500 ps on single cell Need a very dense, high light yield, good timing crystal and a segmentation at the cm2 level in the readout M. Raggi PADME kick-off meeting 20/04/2015

The calorimeter geometry 30 cm Cylindrical shape: radius 150 mm, depth > 200 mm Inner hole 4 cm radius Active volume 13120 cm3 total of 656 crystals 10x10x200 cm3 Material LSO(Ce): high LY, high r, small X0 and RM, short tdecay Material BGO: high LY, high r, small X0 and RM, long tdecay, (free form L3?) Expected performance for LYSO ECAL: s(E)/E =1.1%/√E ⨁ 0.4%/E ⨁1.2% superB calorimeter test at BTF [NIM A 718 (2013) 107–109] s(q) = 3 mm/1.75 m < 2 mrad Angular acceptance 1.5-5 degrees M. Raggi PADME kick-off meeting 20/04/2015

Mu2e LYSO matrix time resolution LYSO performance Mu2e LYSO matrix time resolution SuperB prototype Preliminary NIM A 718 (2013) 107–109 constant term due to trigger Obtained in a test beam at BTF Mu2e DocDb # 5377 Courtesy of Mu2e INFN group. M. Cordelli, G. Corradi, F. Colao, S. Giovannella, F. Happacher, M. Martinia, S. Miscetti, L. Morescalchib, G. Pezzullo, I. Sarra, and S.R. Soleti M. Raggi PADME kick-off meeting 20/04/2015

PADME calorimeter simulation 15 cm long LYSO crystals 20 cm long LYSO crystals M. Raggi PADME kick-off meeting 20/04/2015

MC calorimeter performance Mmiss2(MeV) Missing mass resolution in agreement with toy MC using s(E)/E =1.1%/√E ⨁ 0.4%/E ⨁1.2% [NIM A 718 (2013) 107–109] Differences are ~ 10% Resolution is the result of combination of angular resolution energy resolution and angle energy correlation due to production M. Raggi PADME kick-off meeting 20/04/2015

Cost of a LYSO calorimeter Official quote from Saint Gobain for more than 250 LYSO crystals of 10x10x200 mm3 650 euro/pcs Tolerance 0.1 mm in side and 0.2mm in length. 10-12 weeks after acceptance of order by Saint Gobain Scaling the price to the full calorimeter ~700 pcs ~455Keuro Opportunity to have even smaller crystals explored can reach 4x4x210 mm increasing spatial resolution of the ecal. M. Raggi PADME kick-off meeting 20/04/2015

L3 BGO calorimeter performance M. Raggi PADME kick-off meeting 20/04/2015

PADME ecal using L3 BGO crystals What about collecting the L3 calorimeter BGO? We collected ~80 BGO crystal from L3 calorimeter. Negotiation started by INFN and DOE to get more crystals ~200 pcs. M. Raggi PADME kick-off meeting 20/04/2015

Cutting the L3 BGO crystals On 13 of April we went to Silo (FI) to start crystal cutting procedures We already have 3 crystals in @ Silo firm to get back: 4 crystals 10x10x200 mm optically polished 4 crystals 10x10x220 mm optically polished 4 crystals 10x10x220 mm raw surfaces We expect to get the crystals back for the end of April Present cost of the cutting is 200+VAT per original L3 crystals 4 PADME crystal per 250 euro Cutting order 200 L3 crystals will cost 50Keuro to be compared with 450K M. Raggi PADME kick-off meeting 20/04/2015

Missing mass and Ecal resolution LYSO L3 BGO Are we able to get the same figure of merit with PADME Ecal? M. Raggi PADME kick-off meeting 20/04/2015

Calorimeter photosensors The basic solution for the photo sensors is APD S8664-55 High gain Linear on full range Price 120 euro/pcs (~1000 pcs) SiPM Hamamatsu: MPPC S12572-010P, -015P, -025P 3x3mm2 MPPC 1.3x105 gain Number of cells: 90000, 40000, 14400 Is it linear for 10x10x200 mm3 BGO crystals up to 300-400 MeV? We have few of them to try linearity at the BTF in may Price 17 euro/pcs. Cost of photo sensor solution is ~10 times smaller with SiPM M. Raggi PADME kick-off meeting 20/04/2015

QE and GAIN APD vs SiPM MPPC APD M. Raggi PADME kick-off meeting 20/04/2015

BGO and LYSO with APD M. Raggi PADME kick-off meeting 20/04/2015

Ecal front-end electronics? TOP side View Detector linear voltage regulator - Charge or Transimpedence preamp and detector - Voltage regulator programmable. BOTTOM side View. Charge preamp View. M. Raggi PADME kick-off meeting 20/04/2015

Calorimeter readout V1742 PCI Express CONET2 Controller A3818 12-bit @ 5 GS/s, 1024 samples per event 5, 2.4,1 GS/s selectable sampling frequencies VME64/VME64X (32 ch.) Special analog inputs 2 ch. 1 Vpp input dynamic range with programmable DC offset adj. 16 programmable LVDS I/Os Daisy chain capability A3818 PCI Express CONET2 Controller PCIExpress x8 card 4 independent optical links CONET2 CAEN Proprietary Optical link Compatible Up to 32 CAEN CONET2-compliant Optical slave cards (CAEN VME Bridges or Waveform Digitizer) controlled by a single A3818 Data Transfer rate up to 85MB/s per link M. Raggi PADME kick-off meeting 20/04/2015 Threshold (mV) Minimum effective threshold < 12 mV Small dispersion (RMS = 1.3 mV) High and Low threshold channels can be swapped reducing the minimum threshold

Calorimeter readout model Server All the chain already available test will start in May for the PADME test beam. CAEN V1742 Needs 21 V1742 to collect a total of 656 channels All the board receive the trigger from BTF in daisy chain (50 Hz) On each trigger all the boards digitize all channels and send data to optical links 4 V1742 digitizers connected on each of the 4 optical receiver on A3818 installed in the server 16 V1742 boards per A3818 on a single server M. Raggi PADME kick-off meeting 20/04/2015

Calorimeter readout data load Data transfer rate per each A3818 optical link with 4 V1742 Max samples per channel: 1024 Nbits per sample: 12 Number of channel per link = 32x4 =128ch Without zero suppression = 128x12x1024x50 = 78Mbit/s ~1/8 of the A3818 nominal bandwidth Total Ecal data transfer to server Without zero suppression = 656x12x1024x50 = 403 Mbit/s M. Raggi PADME kick-off meeting 20/04/2015

Calorimeter readout cost Electromagnetic calorimeter readout 656 channels required for digitization 2 VME 6U crates 21 boards V1742 = 672 channels 2 A3818 = 4 boards on each optical link (4Boards/link x 4links/board x 2boards = 32 boars max) 2 server PC with 2 PCIExpress x8 Item Npieces Unit cost Total cost VME 6U crate 2 5000 10K€ VME 1742 22 8000 (CAEN quote 2pcs) 176K€ A3828 2500 (CAEN quote 1pcs) 5K€ Servers 4000 (already have 1) 8K€ Total 200K€+44K€ I.V.A M. Raggi PADME kick-off meeting 20/04/2015

Global Ecal cost estimate Item Solution BGO Solution LYSO Crystals 50Keuro 450Keuro ReadOut 250Keuro 250Kero Front End 100Keuro?? Photo sensors 80K APD/12K MPPc M. Raggi PADME kick-off meeting 20/04/2015

SPARE SLIDES M. Raggi PADME kick-off meeting 20/04/2015